The invention is directed to carton structures of the type which may comprise a box member and cover means therefor, which may be manufactured in knocked-down form having a flat knocked-down configuration and adapted to be erected into box structure at time of use by simple assembly operations, and which preferably provides convenient hand-gripping means for lifting the structure.
Various cartons of this type have been produced, particularly for file and transfer cartons, shipping cartons, as well as packing cartons employed in moving operations. Cartons of this general type are in most instances manufactured from corrugated stock, although fiber board cardboards have been extensively employed where practicable in dependence upon size, capacity, nature of contents, etc. More recently, various types of plastic and plastic or wax impregnated sheet stock, suitable for carton manufacture, have been put on the market.
Such cartons may utilize separate cover members or cover flaps and the like, and in many instances, hand-gripping arrangements have been provided, by means of which the carton may be manually picked up and carried. Such hand-gripping means in cartons of this type have taken the form of hand-receiving openings or holes in opposite carton side walls, a short distance below the top edge of the box, usually an elongated opening. Oftentimes such hand hole is formed of a generaly U-shaped cut to form a flap, integrally connected at its upper edge with the side wall, which is folded inwardly into the carton to reinforce the upper edge of the opening. In other cases merely a portion of the side wall is cut out to form the hand hole. In either case, particularly where the carton is heavily loaded, the side walls tear and deform when the carton is picked up. Likewise, the use of hand holes localizes the points at which the carton may be picked up and carried.
In addition, the carton cannot be packed wall-to-wall at such openings as this would prevent insertion of the fingers into the opening, and thus defeat the purpose thereof.
Further, where cartons of this type utilize a separate cover member, to insure retention thereof on the box member, additional means is required, for example, staples, glue, twine or strapping. Likewise, where cover members of this type are employed on box members provided with hand holes, the cover member provides no reinforcement or support with respect to such hand holes.